可将上图变换下图计算如:
计算R2两端的等效电阻:250*200/250+200=111欧
AB两端的电阻:50欧+111欧=161欧
电路电流:8V/161欧=0.0496A
所以R2两端的电压:111欧*0.0496A=5.5V